The red bumps in the armpits and leg bends can be considered as folliculitis, contact dermatitis, intertriginous rash and other diseases. 1. Folliculitis: patients with red bumps in the armpits and leg bends are mostly considered to be bacterial infection caused by pathogens such as folliculitis, this disease is the main hair follicle involvement of inflammatory skin diseases, mostly manifested as hair follicles as the center of the red pimples, accompanied by occasional itching and pain. When the armpit or leg bend skin and rougher towels, tight clothing friction, or often sweat, or skin trauma prone to occur. 2. Contact dermatitis: the patient’s armpit or leg bend skin is delicate, in contact with allergens or irritants are prone to allergic or irritant reactions, manifested as local redness and swelling of the bumps, accompanied by itching, tingling sensation. 3. Friction rash: acute inflammatory reaction of the skin in the armpits or the bends of the legs due to moisture, friction, etc., which can be manifested as erythema, papules, blisters, vesicles and oozing, accompanied by itching and pain. It is recommended that patients seek timely medical attention to identify the cause and treat the symptoms to avoid delaying the condition.